Seventeen minutes earlier, just 100m around the corner at Queenspark Dr, fire crews were called to extinguish a car on fire up a driveway.
By the time the fire crew got there, the owner had managed to put it out.
The car fire is also being treated as suspicious, Southern Fire Service shift manager Andrew Norris said.
And later this morning police got a call from another Cottonwood St property owner to find a fire had been attempted outside their house.
Mr Norris said the fire never took off and went out by itself. The homeowners only became aware of it when they got up this morning, he said.
Police and fire safety investigators are at the multiple scenes and investigating the three suspicious fires to "see if they are related", Mr Norris said.
